5W-30 instead of 10W-30

[ARCOgraphite]

Based on your statement, an oil will thicken when hot. This is simply not true.

I think slomo is repeating the common layman explanation from many decades ago when multigrades became popular.
"This product "acts" like a 5W at and below freezing but has the needed viscosity of a 30 grade when at operating temperature."

I think the hitch is in "acts like" a 5W. Various 5W-Xx do not evidence a similar viscosity at 0C - they can easily be 100's of cSt apart.

The Winter grade rating relates primarily to the max allowable cP thresholds for pumping and cranking and also apply more to cold gelling and wax formation than the viscometrics at temperatures around and above zero C.

The old solvent refined product required heavily on the use of dewaxing and a very light constituent base to "act" like a 5W when cold. Then a high percentage application of VM to maintain the target viscosity and HTHS when hot. These VM were low quality and likely the primary reason for heavy varnishing and gummed and stuck rings through the 60's and 70's (along with marginal oxidative stability). These products were also highly susceptible to degradation and loss of "in-grade" performance.

Unfortunately old and incorrect explanations are everywhere and even an A.I. co pilot might just pick and quote from one of them
-Arco

 

[ARCOgraphite]

Just dumped some ST Full Syn 15w40 in a 17.5hp single cylinder B&S and the rod knock is slightly quieter. Old oil had loads of glitter for an hour and a half in the sump. May need an engine change before the oil is used up unfortunately

You didn't see me within 100 feet of this machine did you? @SubieRubyRoo needs to know

 

[SubieRubyRoo]

You didn't see me within 100 feet of this machine did you? @SubieRubyRoo needs to know

ARCO sneaking through the back yard…

 

[Lockasiam]

You didn't see me within 100 feet of this machine did you? @SubieRubyRoo needs to know

No haha, I’m not sure why it’s knocking because it was just fine for the longest time then it just started ticking at WOT and knocking on shut down

 

[ARCOgraphite]

That is nonsensical.

We need @buster to chime in a show us how Xom would blend a 5W30 ILSAC RC product vs a "Farm and fleet" 10W30 API SL product or even just the comparable 10W30 ILSAC RC

If I don't get some lunch soon I am going to pass out

 

[ARCOgraphite]

ARCO sneaking through the back yard…
View attachment 279731

I take offense!
I do NOT look anything like Ed Sheeran in a Hamburglar outfit!

- Arco

 

[SubieRubyRoo]

I take offense!
I do NOT look anything like Ed Sheeran in a Hamburglar outfit!

- Arco

Glad we can still laugh.

 

[ARCOgraphite]

 

[NETWizz]

I am reading that it is probably mostly okay. Strange thing is when I read the owner's manual it says 10W-30 is preferred, but I presume they are referring to most folks using cheap conventional oil that may sheer down quickly not to mention many folks are NOT good about doing oil changes.

This is what Honda shows:

It is looking like for the most part they are just saying XW-30 oils flow better in colder condition than plain SAE 30.

In contrast, this is what Yamaha says:

Obviously ANY modern engine oil has a higher API rating than SE even decades ago, yet somehow it mentions JASO MA or MB, which seems to be for a wet clutch. Last I checked, the generator does NOT have any clutch whatsoever; this I am 100% certain of.

 

[Jetronic]

In contrast, this is what Yamaha says:

View attachment 279927

Obviously ANY modern engine oil has a higher API rating than SE even decades ago, yet somehow it mentions JASO MA or MB, which seems to be for a wet clutch. Last I checked, the generator does NOT have any clutch whatsoever; this I am 100% certain of.

the reason for recommending Jaso MA or MB is:
- Yamalube offers lubes with those specs
- the basis of Jaso MA or MB is a current API spec

and just to add, MB is for motorcycle (and specifically scooter) engines without wet clutches.

if a motorcycle oil is used, like yamalube, there would also be extra attention given to the foaming tendencies and the HTHS viscosity would be above 3.5 cP

 

[Skippy722]

I am reading that it is probably mostly okay. Strange thing is when I read the owner's manual it says 10W-30 is preferred, but I presume they are referring to most folks using cheap conventional oil that may sheer down quickly not to mention many folks are NOT good about doing oil changes.

This is what Honda shows:
View attachment 279926

It is looking like for the most part they are just saying XW-30 oils flow better in colder condition than plain SAE 30.

In contrast, this is what Yamaha says:

View attachment 279927

Obviously ANY modern engine oil has a higher API rating than SE even decades ago, yet somehow it mentions JASO MA or MB, which seems to be for a wet clutch. Last I checked, the generator does NOT have any clutch whatsoever; this I am 100% certain of.

I’m running 0w30 in my 6250w Briggs generator. Seems fine for the 20 of 25 hours on the machine so far. Hasn’t burned a drop even running basically non stop for 18 hours.

 

[alarmguy]

What are your thoughts on me switching from 10W-30 Synthetic Havaoline and/or Mobil 1

To the same brands but 5W-30 in my small engines including:

Honda EU2000i
Honda EU2200i

And

Yamaha EF2200iS

The reason I am asking is that I have less than a quart of 10W-30, but because I no longer have a vehicle that takes 5W-30, I am left with about 5 quarts of Havoline Synthetic SN+ and another 5 quarts of Mobil 1 Synthetic SP

Any good reason 10W-30 would be preferred? Heck, when I was a kid the specs were SAE 30 for small engines…

I mean 5W-30 is still a 30 weight oil right only a bit thinner than 10W-30 when vey cold, right? Or is it thinner when hot too?

I have read that oil can sheer down in viscosity… is that anything to worry about? I change it every 25 hours on average.

OR should I put the 5W-30 in my Mazda CX-5 that calls for 0W-20?

Mazda and 5w30 makes PERFECT sense in South Carolina
We lived up near Lake Murray at the time. Summer temps easy 90+ for MONTHS at a time. Was no such thing as a Seabreeze like where we are now.

For 12 years I used 5w30 in our 2012 Skyactive engine. Never a repair, sold it in perfect running condition to someone in our community Nov 2024
At that time the Mazda book said 30 weight was acceptable in Mexico and USA called for the 20

BTW the 5W or 0W is not the weight, its a winter pump ability rating for low temperatures

 

[RDY4WAR]

The newer Skyactiv engines call for 5W-30. A friend has used HPL PCMO 10W-20 in his '22 CX-9 with better results than with the OEM 5W-30. After 5k miles, the 10W-20 had the same KV100 (8.1 cSt) as the OEM 5W-30 at the same ~5% fuel dilution. Their virgin KV100 values are 8.6 cSt and 9.5 cSt respectively. It also had a higher TBN at 5k miles than the OEM fill did at just 200 miles and minimal relative oxidation. This was in the spring and summer and included a trip to myrtle beach.

Personally, I trust a 5W-20 or 10W-20 with <4% Noack and no VII better than I do a 5W-30 or 10W-30 with >10% Noack and loads of VII. In such cases, the base oil viscosity is higher with those 20 grades than the 30 grades and of much better quality meaning less volatile, more shear stable, more oxidation resistant, etc... Where many common API 5W-30 oils are nosing over past 240°F, those no VII 20 grades are relaxing with a cup of tea at 300°F.

What I'm getting at is the quality of the oil is as important or more important than the grade, especially in the heat. It does little good to have a higher kinematic viscosity if it's evaporating and burning around the rings. Obviously, a combination of better quality and higher viscosity (to an extent) is most desirable.

In relation to small engines, that base oil quality is an even bigger deal. Being air-cooled with head temps that can easily reach 350°F and higher, the oil temperature is going to be hotter.

 

[RazorsEdge]

The newer Skyactiv engines call for 5W-30. A friend has used HPL PCMO 10W-20 in his '22 CX-9 with better results than with the OEM 5W-30. After 5k miles, the 10W-20 had the same KV100 (8.1 cSt) as the OEM 5W-30 at the same ~5% fuel dilution. Their virgin KV100 values are 8.6 cSt and 9.5 cSt respectively. It also had a higher TBN at 5k miles than the OEM fill did at just 200 miles and minimal relative oxidation. This was in the spring and summer and included a trip to myrtle beach.

Personally, I trust a 5W-20 or 10W-20 with <4% Noack and no VII better than I do a 5W-30 or 10W-30 with >10% Noack and loads of VII. In such cases, the base oil viscosity is higher with those 20 grades than the 30 grades and of much better quality meaning less volatile, more shear stable, more oxidation resistant, etc... Where many common API 5W-30 oils are nosing over past 240°F, those no VII 20 grades are relaxing with a cup of tea at 300°F.

What I'm getting at is the quality of the oil is as important or more important than the grade, especially in the heat. It does little good to have a higher kinematic viscosity if it's evaporating and burning around the rings. Obviously, a combination of better quality and higher viscosity (to an extent) is most desirable.

In relation to small engines, that base oil quality is an even bigger deal. Being air-cooled with head temps that can easily reach 350°F and higher, the oil temperature is going to be hotter.

Curious,would you be brave enough to run the 10w20 in a riding mower that's used occasionally during the summer?

 

[brillo54]

Curious,would you be brave enough to run the 10w20 in a riding mower that's used occasionally during the summer?

If your mower is water cooled, okay. If air cooled (as most are), no way.

 

[Lockasiam]

Curious,would you be brave enough to run the 10w20 in a riding mower that's used occasionally during the summer?

I wouldn’t.

 

[RDY4WAR]

Curious,would you be brave enough to run the 10w20 in a riding mower that's used occasionally during the summer?

I've been running that 10W-20 in my riding mower (2006 Cub Cadet LT1042) for a few years already. It gets weekly use from April - October in South Carolina's heat. I change it once a year before it goes in storage. I'm not the least bit worried about it.

 

[kschachn]

I've been running that 10W-20 in my riding mower (2006 Cub Cadet LT1042) for a few years already. It gets weekly use from April - October in South Carolina's heat. I change it once a year before it goes in storage. I'm not the least bit worried about it.

What’s the advantage of doing this? Over the 0W-40 I run in my OPE for example.

 

[RDY4WAR]

What’s the advantage of doing this? Over the 0W-40 I run in my OPE for example.

There is none, and I'm not endorsing it. Sometimes, even I don't understand why I do certain things the way I do. I was banned from a mall for riding a kayak down the escalator, and even I don't know what was going through my mind in that moment. My wife thinks I have a touch of the 'tism, and she isn't wrong very often.

In all seriousness though, I have a couple pales of 10W-20 to go through and just felt like using it. Given the quality of that oil, I don't think twice about it.

 

[Rand]

delete me.
for some reason I didnt see there were 2 more pages of replies when I replied.
What I said has been covered